Uterine fibroids are non-cancerous tumors that develop in the wall of uterus. Such fibroids occur in a large percentage of the female population, with some studies indicating up to 40 percent of all women have fibroids. Uterine fibroids can grow over time to be several centimeters in diameter and symptoms can include menorrhagia, reproductive dysfunction, pelvic pressure and pain.
One current treatment of fibroids is hysteroscopic resection or myomectomy which involves transcervical access to the uterus with a hysteroscope together with insertion of a cutting instrument through a working channel in the hysteroscope. The cutting instrument may be a mechanical tissue cutter or an electrosurgical resection device such as a cutting loop. Mechanical cutting devices are disclosed in U.S. Pat. Nos. 7,226,459; 6,032,673 and 5,730,752 and U.S. Published Patent Appl. 2009/0270898. An electrosurgical cutting device is disclosed in U.S. Pat. No. 5,906,615.
As with many surgical resections, fibroid resection can cause bleeding which may in some cases require cauterization. Usually, cauterization would require exchange of the cutting instrument with a cauterization tool in the working channel of the hysterocope. Cauterization might also require use of a different electrosurgical power supply which is capable of delivering a coagulation current which is usually different than the cutting current utilized by the cutting instrument. The need to exchange tools and often power supplies as well can increase the treatment time and complexity.
For these reasons, it would be desirable to provide improved tissue resection apparatus, systems, and methods, particularly for use in resecting fibroids through the working channel of a hysterocope, where both cutting an coagulation could be performed using the same cutting tool and where a single power supply could be used to provide both cutting and coagulation power to the cutting tool. At least some of these objectives will be met by the inventions described below.